The frontier technology ideas presented in this RFS straddle the border between very difficult to science fiction. While these approaches are not our Plan A, we think it’s time to get Plan B ready. They may seem like moonshots now but our goal is to try to come up with technically feasible solutions at realistic costs. If we can do that, we then need to have a global conversation about the tradeoffs.

The request asks for startups to tackle challenges like creating genetically engineered plankton that could live in the open ocean, capturing carbon through photosynthesis and turning the ocean into a much bigger carbon sink than it already is. In a variation on that idea, the desert could be flooded with desalinated water, creating huge pools that could also grow phytoplankton.

The accelerator also wants to fund startups that can accelerate the process of converting CO2 into mineral bicarbonate–something that normally happens over thousands of years as rocks weather. A sped-up process in the ocean could also help counteract acidification. Y Combinator also wants to fund startups that can make enzymes that work outside of living microbes, so they can capture carbon in the ocean without the risk of changing ecosystems.

All of the ideas come with risks. But Y Combinator writes, “It’s time to invest and avidly pursue a new wave of technological solutions to this problem–including those that are risky, unproven, even unlikely to work. It’s time to take big swings at this.”